Researchers reported cases of carnitine palmitoyltransferase 1A (CPT1A) deficiency, a type of long-chain fatty acid oxidation disorder (LCFAOD), in 22 people of Micronesian descent and 3 of Niuean descent, and published their correlation findings in JIMD Reports.
The patients from Micronesia did not show metabolic decompensation before diagnosis or during follow-up, while the patients from Niue presented clinically with symptoms of classic CPT1A deficiency.
Migration pressure partly caused by climate change could be causing an increase in the frequency of people from the Pacific presenting to regional metabolic services around the world, which could explain the increase in the number of reported cases of LCFAOD and other genetic diseases in these populations.
“Knowledge of genotype-phenotype correlations in these populations will therefore inform counseling and treatment of those detected by newborn screening,” the researchers wrote.
Read more about the types of LCFAOD
Symptoms of CPT1A include hypoketotic hypoglycemia and liver dysfunction associated with fasting and illness. In recent years, there has been a significant increase in the incidence of CPT1A deficiency among people living in Hawaii and New Zealand.
Of the 22 patients from Micronesia presented here, 12 lived in New Zealand and 10 lived in Hawaii. They all were homozygous for a CPT1A c.100T>C (p.S34P) variant. CPT1A enzyme activity was 26% of normal in cultured skin fibroblasts.
The 3 patients from Niue were from 2 different families who were all homozygous for a CPT1A c.2122A>C (p.S708R) variant. CPT1A enzyme activity was 4% of normal in the fibroblasts of all 3 people.
“Climate change is expected to place severe migration pressure on many island nations in the Pacific and elsewhere due to sea-level rise and an increase in migration is predicted,” the researchers wrote. It is therefore of great importance to obtain information about the genetic variome of these populations to offer them appropriate genetic counseling and properly manage their disease.
Bernhardt I, Glamuzina E, Dowsett LK, et al. Genotype-phenotype correlations in CPT1A deficiency detected by newborn screening in Pacific populations. JIMD Rep. Published online March 26, 2022. doi:10.1002/jmd2.12271